Abstract:

Wood fiber-polylactic acid(WF-PLA) bio-composites were prepared by kneading. The effect of different kneading temperature and wood fiber moisture on molecular weight and thermal properties of polylactic acid(PLA) in WF-PLA composite were analyzed using gel permeation chromatography(GPC) and differential scanning calorimeter(DSC). The result indicates that kneading temperature had a significant effect on the properties of PLA in WF-PLA composite. The weight mean molecular weight(M_w) of PLA in WF-PLA composite decreased with kneading temperature increased from 180 ℃ to 200 ℃. The number mean molecular weight(M_n) decreased at 200 ℃ only. The molecular polydispersity(PD) of PLA was the lowest at 190 ℃. The melt temperature and cold crystal temperature were different for WF-PLA composite with different kneading temperature. The change of melt temperature was correlative to the molecular weight of PLA. No marked effect induced by wood fiber moisture to molecular weight and thermal properties of PLA of WF-PLA bio-composite.

Key words: WF-PLA composite, molecular weight, thermal properties, wood fiber moisture, polylactic acid